Surgical dressings, bandages and the like



March 17, 1959 q. BUNYAN 2,877,765

SURGICAL DRESSINGS. BNDAGEIS AND THE LIKE.' A

Filed Jul;r l, 1957 i .In Q5 m @im @wz www@ Mgw FIGB FIG

FIGB

Unite States Patenti SURGICAL DRESSINGS, BANDAGES AND THE LIKE John Bunyan, London, England Application July 1, 1957, Serial No. 669,329 c Claims priority, application Great Britain July 13, 1956 zo Claims. (Cl. 12s- 156)A h This invention relates to improvements in and relatmg to surgical dressings, bandages and the like.

2,877,765 Patentedliu/lm'. 17, 1959 ICC when applied to an open wound, may be readily removed therefrom without diiculty and without causing discomtion from the wound, it is necessary to provide perfora- The principal object of the invention is to provide an improved surgical dressing, which, whilst permitting adequate drainage of a wound to which it is applied, can be readily removed therefrom without causing discomfort to the patient.

Another object of the'invention is to provide'an improved surgical'dressing of the kind comprising a layer of absorbent material arranged between layers of perforated plastic, e. g. thermoplastic material, which, whilst permitting the passage of exudation from a wound to-the absorbent ,materiaL will not become adherent to the skin tissues of the patient and can be readily removed therefrom. v

Another object is to provide an improved construction of plastic outer covering or gauze for the absorbent material of a surgical dressing which-does not suffer from the deficiencies of plastic coverings heretofore used or proposed.

The manner in which the above and othery objects of the invention are attained `will be more readily under-- stood from the following description taken `in conjunction with the accompanying diagrammatic drawings, which illustrate some preferred embodiments of the invention, it being clearly understood that the invention is in no way limited thereto or thereby, but that the true scope of the invention is defined in and .by the appended claims.

In the drawings: Figure l shows one form of plastic, e. g. thermoplastic outer covering for a'surgical dressing embodying the invention,

Figure 2 is a similar view showing a modified` construction, f

Figure 3 shows another form of outer `covering according to the inventiom. v

- Figure '4 shows a still further modification and l Figu`re5 shows a portion `of a surgical dressing 'embodying two plastic outer coverings as shown in vFigure 1.

In the past surgicaldressings have mainly consisted of a' pad or wad of absorbent material, such ascotton wool, enclosedV in an outer covering of cotton gauze,or like woven material, which is applied to an open wound for the purpose of absorbing exndation from the wound and keeping the latter clean. Suchdressings, whilst -being.` satisfactory for their intended purpose, havey the .dis-f' advantage that considerabley discomfort,A if no t pain, issuffered by a patient'during the removal of such a dressing from the wound owing to the fact thatthe gauze threads and portions of the absorbent material, which have penetrated through the interstices of the gauze and have become saturated with exudation, tend to adhere-"to the iiesh of the patient and considerable diiiculty is experienced in drawing the dressing away from the wound.

In. order to overcome this disadvantage, it has been suggested to employ, in place of the usual cotton gauze of a dressing-,a sheet or filmvof thermoplastic material, such as polythene. Ithasbeenlound that pol-ythene,

tions in the otherwise imperforate sheet. rFor this purpose, polythene sheets containing a plurality of circular holes or perforations or a plurality of narrow straightsided slits have been proposed for use with surgical dressings.

Such dressings have, however," not proved satisfactory in use, as, whilst ordinary imperforate plastic sheets does not adhere to a wound and can be readily removed 'therefrom, this is not the case if the plastic sheet is provided with circular openings or straight sided slits. This is thought to be due to the. fact that' although such a dressing when initially placed 'on awound will lie close to, and closely follow the contour of, the patients limb or other body part, the perforations or slits permitting the 1 requisite drainage ofliquid from the wound, whilstfpreventing penetration of the absorbent material through the perforations or slits and into contact with 'the patients body, any unavoidable movement of the infected part of theA patients body, whilstv the dressing is in position, will cause relative movement between the skin andl the dressing with the resultthatthe edges' of the perforations or'slits will be displacedcausing 'a rucking up of the plastic' sheet. at the said edges. The peripheral edges or the sides of the slits thus nol longer wholly contact the skin, but spaces are formed through which the absorbent material canipenetrate and adhere to the patients skin tissues. QI-,have no'w found that the above difficulties and disadvantages in the use of plastic materialin surgical dresse ings can be overcome in a simple and efiicient manner if the material is provided with slits of a definite predetermined conliguration. v'

The invention thus broadly contemplates the provision of a plastic outer covering for a surgical dressing in which the openings provided therein fordrainage'purposes are in the form of elongated curvilinear or bow-shaped slits. The curvilinear vor bow-shaped slits should beso dimensioned that, rwhen the material is applied to a patients limb or other body part,` the opposed. edges of` 1 the' slits lie co-planar with each other and vhence with the p sheet-like layer as a whole and in close conformity with the contour of the limb or body part and tend to retain' their co-planar relationship without relative displacement in use.r Y-

--In applying the invention to a surgical dressingyay wad or sheetof absorbent material, such as cotton wool', is located between two layers or films of yplastic material, atleast that layer intended for application to a wound being provided with a pluralityof curvilinear or bow' shaped slits in accordance with the invention.

By this means, whilst the slits are sufficient to allow the free passage of exudation from the wound to' the' absorbent material of the dressing,v there will be little or no tendency for loose threads of the absorbent material overlying the slits to' pass therethrough and come' 'into contact with the wound owingto the fact that the slits do not tend to open or ruck-up in use. The dressing can,

therefore, readily be removed from the wound when re-- quired without any part thereof having adhered tothe 'patients skin and thereby causing discomfort or pain to the patient during removal.

v The slits are preferably arranged in evenly spaced parallel rows extending over the whole area of the plastic sheet, each row comprising any desired number of evenly "spaced slits. All the slits may lie with their convex edges 1 extending in the4 same direction throughout the sheet, but it will be found advantageous if the slits in one row are oppositely disposed with respect to those in the immediately adjacent rows. Moreover, the slits in any onev row should preferably be staggered with respect tok those iny the immediately adjacent row or rows.

The length and extent of curvilinearity of the slits are not thought to be critical provided that thechordal distance between the ends of the slit is always more than twice that` of the perpendicular-from chord to the highest point of the curve.

The slits may advantageously have the form ofcircular or elliptical arcs, the dimensions of which areless than a semi-circumference.

The number and relative positions of the slits should be so chosen as to provide themaximum area for. drainage purposes without thereby` unduly weakening the material.

The plastic material employed in carryingV out the invention preferably consistsof'polythene although otherplastic or thermoplastic substances, such as polyvinyl chloride, which may be formed into tiexiblesheets, may, if` desired, be used.

If-desired, the plastic-material maybe provided with a plurality ofy grooves and ridgesl constituting capillary paths, which assist the iiow of the exudation fluid. The capillary paths may be arranged parallel to onetanother` or. they may radiate from a common centre and may extend throughout the material or be located only adjacent the slits.

As will be readily` appreciated, the plastic covering may, if desired, in addition beprovided with any desired number v of perforationst or` pinholes further' to assisty the disposal t of exudation uid.

Referring now-to the.. drawings, and`tirst toFigure `1,' my -improved outer covering for a surgical'gdressing comprises a sheet ofl thermoplastic material 1, suchy for exampley as-poly-thene, although any othersuitablefplastic material suclr aspolyvinylchloridemay be used, having. formed therein-a pluralityA of spaced parallel rows of spaced slits 2. As shown, each slit 2 isof elongated curvilinear form constituting an elliptical arc of an overall length equal to less than a semi-circumference. Thus the distance` between the ends- 2a and 2b of each slit isv more than twice that of the perpendicular from the chord 3 to the highest point ofthe curve.

With .this construction it will be found that the -opposed sidevedges ofthe slit 2 will always lie co-planar with .one another -when applied to a-wounded body partl and even, on `relativemovement taking-place in use between the-.body part andthevcovering, willtend to maintainV this co-planar-relationship-thereby preventing or reducingto a minimum thepossibility of a surgical bandage incorporating my improved covering from sticking tothe vwoundrandbeng ydifficult-to remove owing `to-loose threads `ortibres ofthe. absorbent material of the dressinghaving-penetrated` through the slits.l

Thenumber of'slitszcperrowfandthe numbenof rowsofslitsmay be chosen las Vdesired or according-to requirements, but it.,V will :be-found'desirable in practice to provide asmany,slits;per row -andtoqspace .the rows as-cllosely as possible v.,consistent'with maintaining-rade-v quate strength in theplastiosheet.

In the `embodiment shown in Figure l, all they,slits 2Y lie lin thesame direction, that is.to say', the convex-edgesof the slits` in one row face the concave Yedges :in theA nextadjacent rowand viceversa, whilst all the slits in any: given row face in the same direction.

In Figure .2 theconstruction is similar to that shownin Figure l in that all the slits-2 in any given row face, in the same direction, but the slits in alternate rows face in opposite directions, that is to saytheA concave edges of the slits 2 in any given row, for example, rowl aA face the-concave edges ofthe slits in the-next adjacent` row V` b. Moreover, the slits-.2.in...rowrbearestaggeredf 4- with respect to those in -row a, so that each slit 2 in row b partly overlaps two adjacent slits 2 in the adjacent rows a.

This construction will be found to give increased strength to the material and is the preferred construction.

The construction shown in Figure 3 is similar to that shown in Figure 2, except that the slits 2, instead of being constituted by elliptical arcs are each of part polygonal form comprising a number of interconnected chords or Ibases of segments of the corresponding ellipse. The edges of the slits 2 thus in this case do not lie wholly on the circumference of an ellipse or circle, but extend as a series of straight-sided slit portions, c, d, e, f, g, angularly related to one another. In the Figure 3 construction, the sheet 1 is also provided' throughout the area thereof with a plurality of small perforations or pinholes 4 further to assist the flow of exudation therethrough. The presence of such perforations 4 is `not essential and has the disadvantage of tending to weaken the structure as a whole.

Figurev 4 shows a further modification of the constructionV shown' in FigureV 2, yaccording to which theA plastic sheet 1 isprovidedI withtal number of corrugations extending from the inner or concave edges of the slits for a short distance either parallel to one another as shown at 5 in Figure 4 or radially asshown at 6 in this-figure. Such corrugations form capillary paths which further assist the-flow of the exudation tiuid from the wound.

Finally, Figure 5 illustrates a surgical dressing comprising a pad or wadding of absorbent material 7, such as cotton wool, having on the opposite sides thereof` an outercovering 8 of the kind shown in Figure 2.

A` surgical dressing embodying the invention will be found equally. suitable-for usein satisfactorily disposing of 'highgand low viscosity 'exudates It is to be understood that the term surgical dressing"=as1used herein-is intended tol have the meaning'generally assigned to` it inl theart of medicine andv surgery and includes bandages such as form part of first-aid equipment, and also bed-sheets carrying absorbent material on which a patient is placed.

It is further to be understood that the expression curvilinear as used herein and in the claims to define the shape of the slits is intended to include a part polygonal construction comprising a plurality of interconnected linear slit portions constituting chords or the bases of adjacentV segments of a circular or elliptical arc.

What I claim is:

1; An outer covering for the absorbent material of a surgical dressing, as hereinbefore defined, comprising atk sheetlikelayer of exible plastic-material having therein a plurality of openings for allowing the passage there-y through of-'exudation from-a-wound, said openings having-theform ,ofV elongatedcurvilinear slits, and thcV opposed edgesof saidl slits-lying in substantially co-planar relation to-the sheet-like layer asa' whole.

2. An outer covering for theabsorbent material ofa-surgical dressing-as hereinbefore defined comprising a sheet-like layer of fiexible plastic material adapted to enclose saiddressing on at least one4 side thereofand having therein a plurality of substantially parallel spaced rows`ofjspaced openings, said'openings havingy the form ofelongated curvilinear slits, and the opposed edges-.ofA saidy slitsglying in vsubstantially lco-planar relationy to the sheet-like layer as a whole.

3. An outer coveringfor4 the absorbent material ofa` surgical dressing ashereinbefore defined, said coveringA comprising a-sheetlike` layer of tiexible plastic material adapted toenclosesaid dressingon at least one-side thereof ,'and;A having thereina plurality'of substantially parallell rows of'spaced openings, said openings having` the form ofrelongated curvilinear slitsl so dimensioned that:-'th`c chordal distance between the -ends of theslit is always Amore than twice that of the` perpendicular from the' chord to the highest point of the curve.l

4. An outer covering for the absorbent material of a surgical dressing as hereinbefore defined for application to a wounded body part, said coveringcomprising a sheet-like layer of iiexible plastic material adapted to enclose said dressing on at least one side thereof and having therein a plurality of substantially parallel spaced rows of spaced openings, for Aallowing thepassage therethrough of exudation, said openings having the form of elongated curvilinear slits, so dimensioned that the chordal distance between the ends of each slit is always more than twice that of the perpendicular from the chord to the highest point of the curve whereby when the material is applied to the wounded body part, the opposed edges of the slits lie co-planar in close conformity with the contour of said body part, and tend to retain their co-planar relationship without relative displacement in use.

5. An outer covering for the absorbent material of a surgical dressing as hereinbefore defined comprising a sheet-like layer of flexible plastic material having therein a plurality of substantially parallel spaced rows of spaced openings for allowing the passage therethrough of exudation, said openings having the form of circular arc-like slits the dimensions of which are less than a semi-circumference thereof.

6. An outer covering for the absorbent material of a surgical dressing as hereinbefore defined comprising a sheet-like layer of exible plastic material having therein a plurality of substantially parallel spaced rows of spaced openings for allowing the passage therethrough of exudation, said openings having the form of elliptical arc-like slits the dimensions of which are less than a semi-circumference thereof. l

7. A surgical dressing as hereinbefore deiined for application to a wounded body part comprising a layer of absorbent material having on at least one side thereof a sheet-like layer of flexible plastic material, said material having therein a plurality of openings for allowing the passage therethrough of exudation from a wound, said openings having the form of elongated curvilinear slits.

8. A surgical dressing as hereinbefore defined for application to a wounded body part comprising a layer of absorbent material having on at least one side thereof a sheet-like layer of liexible plastic material, said material having therein a plurality of substantially parallel spaced rows of spaced openings for allowing the passage therethrough of exudation, said openings having the form of elongated curvilinear slits.

9. A surgical dressing as hereinbefore defined for application to a wounded body part comprising a layer of absorbent material having on at least one side thereof a sheet-like layer of flexible plastic material, said material having therein a plurality of substantially parallel spaced rows of spaced openings, for allowing the passage therethrough of exudation, said openings having the form of elongated curvilinear slits so dimensioned that the chordal distance between the ends of the slit is always more than twice that of the perpendicular from the chord to the highest point of the curve.

l0. A surgical dressing as hereinbefore defined for application to a wounded body part comprising a layer of absorbent material having on at least one side thereof a sheet-like layer of flexible plastic material, said material having therein a plurality of substantially parallel spaced rows of spaced openings for allowing the passage of exudation from the body part to the absorbent material, said openings having the form of circular arc-like slits, the dimensions of which are less than a semicircumference.

1l. A surgical dressing as hereinbefore dened for application to a wounded body part comprising a layer of absorbent material having on at least one side thereof a sheet-like layer of flexible plastic material, said material having therein a plurality of substantially parallelvspzaced row's of spaced openings for allowing :the passage of exudation from the body part to the absorbent material, said openings having the form of Velliptical arc-like' slits,` the dimensions of which are less than a semi-circumference. 4

12. A surgical dressing as hereinbefore delined for application to a wounded body part comprising a layer of absorbent material having on at least one side'thereof a sheet-like layer of polythene plastic material, said material having therein aplurality of substantially parallel spaced rows of spaced openings forl allowing thepassage of exudation from the body part to the absorbent material, said openings having the form of elliptical arc-like slits, the dimensions of which are less than a semicircumference.

13. A surgical dressing as hereinbefore defined for application to a wounded body part comprising a layer of absorbent material having on at least one side thereof a sheet-like layer of iiexible plastic material, said material having therein a plurality of substantially parallel spaced rows of spaced openings, said openings having the form of elongated curvilinear slits, the slits in one row being oppositely disposed with respect to the slits in the immediately adjacent rows.

14. A surgical dressing as hereinbefore dened for application to a wounded body part comprising a layer of absorbent material having on at least one side thereof a sheet-like layer of iiexible plastic material, said material having therein a plurality of substantially parallel spaced rows of spaced openings, said openings having the form of elongated curvilinear slits, the slits in'one row being staggered with respect to those in the next adjacent row on either side thereof.

15. A surgical dressing as hereinbefore defined for application to a wounded body part comprising a layer of absorbent material, a layer of flexible plastic material on each opposed side of said absorbent layer, at least one of said plastic layers having therein a plurality of substantially parallel spaced rows of spaced openings, said openings having the form of elongated curvilinear slits, the slits in one row being staggered with respect to those in the immediately adjacent rows and the slits in one row being oppositely disposed with respect to those in the next adjacent row on either side thereof.

16. An outer covering for the absorbent material of a surgical dressing as hereinbefore defined comprising a sheet-like layer of iiexible plastic material having therein a plurality of openings for allowing the passage therethrough of exudation, said openings having the form of elongated curvilinear slits and the plastic material atleast adjacent said slits having formed therein a plurality of grooves and ridges constituting capillary paths assisting the flow of the exudation uid.

17. A surgical dressing as hereinbefore delined for application to a wounded body part comprising a layer of absorbent material and on at least one side thereof a sheet-like layer of iiexible plastic material, said material having thereon a plurality of openings for allowing the passage therethrough of exudation from the body part, said openings having the form of elongated curvilinear slits and the plastic material at least adjacent said slits having formed therein a plurality of grooves constituting capillary paths assisting the iow of the exudation uid.

18. An outer covering for the absorbent material of a surgical dressing as hereinbefore defined comprising a sheet-like layer of flexible plastic material having therein a plurality of substantially parallel spaced rows of spaced openings, said openings having the form of elongated curvilinear slits, the slits in one row being oppositely disposed with respect to the slits in the immediately adjacent rows.

19. An outer covering for the absorbent material of a surgical dressing as hereinbefore defined comprising a sheet-like layer of exible plastic material having therein a plurality, of`substantially parallelspaced' rows of spaced openings, said` openings'having, the form off elongated curvilinear slits, vthe slits in one row being staggered'with respect to. those inthe next adjacent row on either side thereof; and the opposed`ed'ges of Asaid'slits lying in substantially co-planar relation to the sheet-like layer as a whole.

2'0`. An outer covering for the absorbent material of a surgical dressing as hereinbefore dened comprising a sheet-like layer of flexible plastic material having therein4 a. plurality of. substantiallyl parallel spaced rows of spaced.' openings, said. openings having the form of elon- 8 gated curvilinear slits, the slts'in one row heiug,v oppositely disposed'with respect to the" slits inthe inimadiately adjacent rows andthe slits in one row heingstaggered'witli respect to those in the next adjacent row on either side thereofl Refrencesitedlin the file ofE this patent UNITEDl STATESVPA'IENTSA 2,703,683 Gross Mar. 1,1955 FOREIGN PATENTSj 402,870 Great Britain Dec. 14, 1933 

